Diary/Shared/ExceptionHandlingMiddleware.cs

namespace Diary.Shared
{
	public partial class ExceptionHandlingMiddleware : IMiddleware
	{
		private readonly ILogger<ExceptionHandlingMiddleware> _logger;

		public ExceptionHandlingMiddleware(ILogger<ExceptionHandlingMiddleware> logger)
		{
			_logger = logger;
		}

		public async Task InvokeAsync(HttpContext context, RequestDelegate next)
		{
			try
			{
				await next(context);
			}
			catch (Exception e)
			{
				_logger.LogError(e, "Error received from ExceptionHandlingMiddleware");
				await HandleExceptionAsync(context, e);
			}
		}

		private static async Task HandleExceptionAsync(HttpContext httpContext, Exception exception)
		{
			ExceptionDetails exceptionDetails;
			httpContext.Response.ContentType = "application/json";

			if (exception.InnerException is AppException)
			{
				exception = exception.InnerException;
			}

			if (exception is AppException applicationException)
			{
				httpContext.Response.StatusCode = (int)applicationException.StatusCode;

				exceptionDetails = new()
				{
					Message = applicationException.Message,
					Title = applicationException.Title
				};
			}
			else
			{
				httpContext.Response.StatusCode = 500;

				exceptionDetails = new()
				{
					Message = exception.Message,
					Title = "API Error"
				};
			}

			await httpContext.Response.WriteAsync(exceptionDetails.ToString());
		}
	}
}